Sumire's husband has recently developed erectile dysfunction, so she's been trying to cope with the frustration by exercising. One day, she catches her son-in-law, Shinya, secretly masturbating while watching her. Unable to get his massive cock out of her mind, she offers to help him ejaculate, claiming she needs to "release" his powerful erection. Day and night, her mother-in-law relentlessly propositions her, driving Shinya to the brink of insanity with her constant advances.
